1. Field of the Invention
The present invention relates to a compensator for the compensation of axial movements of pipe conduits and including a first sleeve, a second sleeve and a bellows, the first sleeve intended to be mounted to a section of a pipe conduit, the second sleeve intended to be mounted to an opposite section of the pipe conduit and the bellows interconnecting said first and said second sleeves, and including a guiding means for a mutual axial guiding of said first and said second sleeves which guiding means rests slidingly displaceable on at least one of said sleeves.
Pipe conduits are subject to thermically produced changes of their axial length. These changes of the longitudinal extent of the pipe conduits are taken up by various structures such as compensators for compensating axial movements. Such compensators comprise generally two sleeves which at their respective ends are rigidly mounted to the next following pipe conduit section and are interconnected at their respective opposite ends by means of a bellows, a spring bellows. Such bellows is, furthermore, bridged by a guiding means by which the two sleeves are mutually guided.
2. Description of the Prior Art
Such guiding means of the prior art comprise a pipe section having an inner diameter which is larger than the outer diameter of the bellows. One end of such pipe section is welded to an annular flange which in turn is welded to one of the sleeves of the compensator. The other end of the pipe section rests slidingly on a further annular flange which again in turn is welded to the other sleeve and at the surface area being the interface between the other end of the sleeve and the further annular flange there is provided an additional guiding member which is operative to guide the pipe section axially relative to the respective sleeve, however, at the same time to prevent a relative rotating therebetween. These known designs are rather intrinsic because they necessitate a large amount of relatively expensive material, resting interfaces and sliding surfaces which must be exactly machined and worked as well as welding beads of exceedingly large dimensions. When a pipe conduit is completed it often is subjected to a pressure test, e.g. a hydraulic test. During such testing it is necessary to protect the compensator and specifically its bellows section against overly large stresses. Such can be arrived at by utilizing a temporary operating blocking means. According to the prior art only such blocking means have been used which are accessible from the outside, leading to the fact, that in case of a pipe conduit laid in a trench such trench could be filled in not earlier than after having made such pressure test. This is obviously quite time consuming, expensive and cumbersome.